1 files changed, 17 insertions, 0 deletions
diff --git a/pc-bios/s390-ccw/helper.h b/pc-bios/s390-ccw/helper.h
index 78d5bc7442..32a453b634 100644
--- a/pc-bios/s390-ccw/helper.h
+++ b/pc-bios/s390-ccw/helper.h
@@ -14,6 +14,7 @@
 #define S390_CCW_HELPER_H
 
 #include "s390-ccw.h"
+#include "s390-time.h"
 
 /* Avoids compiler warnings when casting a pointer to a u32 */
 static inline uint32_t ptr2u32(void *ptr)
@@ -28,4 +29,20 @@ static inline void *u32toptr(uint32_t n)
     return (void *)(uint64_t)n;
 }
 
+static inline void yield(void)
+{
+    asm volatile ("diag 0,0,0x44"
+                  : :
+                  : "memory", "cc");
+}
+
+static inline void sleep(unsigned int seconds)
+{
+    ulong target = get_time_seconds() + seconds;
+
+    while (get_time_seconds() < target) {
+        yield();
+    }
+}
+
 #endif